BALLPOINT PEN CHIP, BALLPOINT PEN AND METHOD FOR MANUFACTURING BALLPOINT PEN CHIP

摘要

PROBLEM TO BE SOLVED: To provide a ballpoint pen chip that enables insertion of a spiral spring into a chip body more reliably.SOLUTION: A ballpoint pen chip 10 is a chip in which a ball 40 is mounted in the tip of a chip body 20 and a spiral spring 30 for biasing the ball 40 is inserted into the chip body 20. The chip body 20 includes: a ball housing part 21 for housing the ball 40; a large diameter ink hole 26 extending in the axial direction of the chip body 20; a small diameter ink hole 24 with an internal diameter smaller than that of the large diameter ink hole 26; and a communicating part 22 bringing the ball housing part 21 into communication with the small diameter ink hole 24, and having an ink flow groove 23 extending in the axial direction formed on the wall surface thereof. The spiral spring 30 has a straight part 32 and a small diameter spring part 34 connected to a rear end of the straight part 32. The small diameter spring part 34 has an outer diameter substantially coinciding with the internal diameter of the small diameter ink hole 24, and a portion thereof is disposed in the small diameter ink hole 24.